Patients with severe chronic alcoholic pancreatitis (with or without associated liver disease), alcoholic cirrhosis, benign extrahepatic obstructive jaundice and cholecystitis may have elevated plasma CEA values. The elevated values in these patients may be due to the failure of the liver (a) to metabolize or (b) to excrete normally low levels of circulating CEA. A method is needed which will distinguish such patients from those with early pancreatic and biliary tract cancer and primary or metastatic cancer of the liver. CEA and CEA-like substances are produced by these tumors. The respective secretions (bile duct and liver bile and pancreatic juice) may have high concentrations which are emptied into the duodenal juice. A modified CEA radioimmuno assay will be used to identify CEA-like substances which will be chromatographically separated and immunochemically characterized and compared to CEA by (a) absorption, (b) immunodiffusion, (c) immunoelectrophoresis, and (d) competitive binding studies. This information is necessary if we are to distinguish among these glycoproteins. Specific assays can then be developed for the early diagnosis of cancer of the pancreas, biliary tract, and liver: Part I. Pathobiology of CEA (and Other Tumor Markers) in Malignancies of the Hepato-Biliary-Pancreatic System. Part II. Immunochemical Identification and Characterization of CEA and CEA-like Substances in Upper Gastrointestinal Secretions.